Jackson etal
burner control apparatus



Nov. 1, 1966 w. F. JACKSON ETAL 3,232,325

BURNER CONTROL APPARATUS Filed June 5, 1964 ATTORNEYK United StatesPatent 3,282,325 BURNER CQNTlROL APPARATUS Wilbur F. Jackson, RollingHills, and John W. Wright, Long Beach, Calif., assiguors to Robertsha-wControls Company, Richmond, Va., a corporation of Delaware Filed June 3,1964, Ser. No. 372,22tl 3 Claims. (Cl. 158-129) This invention relatesto fuel burner control apparatus and in particular to a combined pilotflow valve and thermal switch arrangement performing an automatic pilotfunction in fuel burning systems such as gas operated heating and/ orcooling systems.

In certain installations, the flow of gas to the fuel burning apparatusis controlled by a gas control valve which monitors a pilot flow of gasto a pilot burner and a main flow of gas is effected by various types ofmain valves, such as a solenoid valve, a heat motor valve, or adiaphragm valve. operating on the bleed principle; each of these typesof main valves include an electric actuator in series with a temperatureresponsive device, such as a room thermostat, to cause main valveactuation automatically in accordance with deviations from a presettemperature in the space being temperature controlled. In order toobtain 100% shut off of the gas flow with such main valve, it has beennecessary to provide the gas control valve with a safety pilot valve toshut off gas how to both main and pilot burners upon extinguishment ofthe pilot burner flame. Such an arrangement required an expensive andcomplicated control device as by incorporating the safety pilot valveand a manually shut off cock with the main valve and utilizing anautomatic pilot operator to shut off the gas flow.

It is therefore, an object of the present invention to eliminate theneed for automatic pilot operators in the control valve of fuel burnersystems having main'and pilot flow burners.

The present invention has another object in that the electric actuatorof a main control valve is electrically connected to the switch of apilot valve and switch combination.

Another object of this invention is to construct a combined pilot valveand pilot switch in a simple and economical manner.

It is another object of this invention to provide a pilot valve andswitch combination with a bypass flow of fuel during a resettingoperation.

The present invention has a further object in that a fuel bypass fiow toa pilot burner is established without actuation of the pilot valve andswitch combination.

A further object of this invention is to combine a pilot burner, pilotflow valve means and thermal switch means in a unitary housing.

In a preferred embodiment of the present invention, control apparatusfor a fuel burning system having main and pilot burners includes a mainvalve means with an electric actuator for controlling a main flow offuel to the main burner, pilot valve means for controlling a flow of uelto the :pilot lburne-r which is disposed adjacent flame responsivemeans, switch means electrically connected to the electric actuator, andlever means operatively connected between the pilot valve means and theswitch for combined operation thereof, the lever means being movable inresponse to movement of said flame responsive means to effect a combinedoperation of the pilot valve means and the main valve means.

Additional features and advantages of the present invention will becomeapparent from the following description of the preferred embodiment,taken in connection with the accompanying drawing. The single figure ofthe drawing is a schematic arrangement with parts in sectionillustrating a fuel burning system incorporating the present invention.

The control apparatus shown in the drawing includes a gas control devicehousing or casing, indicated generally at 10, having an inlet 12connected to a source of gaseous fuel (not shown) and an outlet 14connected to the main burner apparatus 16 of a fuel burning system, suchas gas operated heating and/or cooling systems. The inlet and outletsare separated by a main valve which may be of any suitable type but forthe purposes of this description, is shown as a diaphragm valve 18having a main valve chamber 20 communicating with the inlet 12 andhaving an operating pressure chamber 22 on the undersides of diaphragmvalve 18. A bleed flow passage 24 on the inlet side of valve 18 hascommunication with two branch passages, one such passage 26 leading tothe operating pressure chamber 22 and the other passage 28 =leading tothe outlet side of valve 18. A fiow restrictor 29 is disposed in thepassage 24 upstream of the branch passage 26 to provide the bleed linepressure drop required to assure operation of the diaphragm valve 18. Anelectrically actuated ball valve 30 operatively disposed in the bleedflow passage 28 controls the pressure in the operating pressure chamber22 to effect operation of the main d-iaphgram valve 18 which is biasedtoward its closed position by a helical coil spring 32. Whenever theball valve 30 is closed, the bleed fiow through passage 28 is cut offand the bleed flow from passage 24 feeds into the operating pressurechamber 22 whereby the underside of the diaphragm valve 18 is subject toinlet pressure and is closed by the coil spring 32.

The ball valve 36 is actuated as by a bimetal heat motor actuator or byelectric means in the form of an electromagnet having a U-s-haped core34, a coil 36 and a keeper lever 38 intermediately fulcrummed on one legof the core 34. The free end of lever 38 carries the operating stem 40of the ball valve 30 and a tension spring 42 normally biases theopposite end away from the core 34 and the stem 40 and the valve 30toward a valve closed position.

Adjacent inlet 12, the casing 10 is provided with a pilot flow passage44 which is branched into two pilot flow passages 46 and 48. The pilotflow pass-age 46 defines a regular flow for pilot burner fuel while thepassage 48 defines a bypass or reset flow for pilot burner fuel.Intermediate the passage 48, a normally closed valve 50 cuts oil. thereset flow. A push stem 52 on valve 50 protrudes through the wall ofcasing 10 and carries a push button 54 on its end; a coil spring 56encircles the protruding portion of stem 52 and is mounted incompression between the wall of casing 10 and the underside of pushbutton 54.

As is illustrated in the drawing, a control device housing 55 is securedadjacent the main burner 16 in such position that its burner is utilizedto ignite the main burner 16. The housing 55 includes a pair of pilotflow inlet passages 56 and 58, with the passage 56 externally connectedto the outlet of the pilot flow passage 46 and with the passage 58externally connected to the outlet of the reset pilot flow passage 48.The pilot flow passage 58 communicates with an internal passage 60 whichfeeds a pilot burner 62; the pilot burner 62 includes the structure of anozzle portion 64 adjacent an opening in the wall of the housing 55which is covered by a deflector 66 having a lower cylindrical member andan upper flat plate axially inclined thereto.

A flow of pilot burner fuel from passage 56 also feeds into the internalpassage 60 but the flow thereof is controlled by valve means 68 in theform of a movable valve member. The valve member 68 is secured to oneend of an operating lever 70 for actuation thereby. Intermediate itsends, the lever 70 is deformed to define a semispherical detent 72 onits upper surface. A coil spring 74 mounted in compression between abottom wall recess 76 in the housing 55 and the undersurface of thedetent 72 which is thus biased into engagement with flame responsivemeans.

The flame responsive means is of the rod and tube type in which a tubeelement 7 8 has an outer portion disposed adjacent the pilot burnerdeflector 66 to sense the existence of a flame therefrom. The tube hasan inner portion extending through a suitable opening in the wall of thehousing 55 and secured thereto as by a press fit or by a lock nut 80.The tube 7 8 defines a cylindrical shell for an actuating rod which hasan operating portion 82 disposed in the housing 55 in engagement withthe detent 72 on the lever 70. The rod and tube of the flame responsivemeans are made of different material to effect thermal expansion andcontraction as is well known in the art; of course other types of flameresponsive means may be utilized.

The undersurface of the other end of the lever 70 engages a switchactuator 84 which extends through a bore in the bottom wall of housing55; an O-ring seal encircling the inner part of the actuator 84 providesa seal 85 for the housing bore. As is illustrated in the drawing, theactuator 84 extends into an external recess 86 which is closed by aflush mounted switch block 88. A first contact 90 is fixed on the block88 and a second contact 92 is mounted on a current carrying spring blade94 normally biases the movable contact 92 away from the fixed contact 90and into engagement with the end of electric switch actuator 84.

The various electrical components and the electrical circuitry thereforwill be described in appropriate places in the following description ofthe sequence of operation of the present invention. The relativepositions of the various valves and switches are shown in the drawing intheir shut conditions, i.e., the main burner 16 and the pilot burner 62are not burning, thus, main valve 18 is closed, bleed flow valve 30 isclosed, reset pilot flow valve 50 is closed, regular pilot flow valve 68is closed and electric switch 90-92 is opened.

In order to place the device in operation, the push button 54 ismanually depressed to open the valve 50 and a flow of pilot burner fuelmay be traced from inlet 12, through the pilot flow passage 44, thebranch passage 48, the pilot flow passage 58 and the internal passage 60to the pilot burner 62 where it is ignited as by a match. The pilotburner flame is thus deflected toward the adjacent flame responsivemeans 78 which causes expansion thereof so that the inner operator 82depresses the lever 70 against the bias of the coil spring 74. With thelever 70 in its depressed position, the pilot flow valve 68 is opened;the push button 54 may be released to closed valve 50 because theregular flow of pilot burner fuel is established from branch 46, throughthe inlet passage 56 to the internal passage 60.

The depressed position of the lever 70 also causes the closure ofelectric switch contacts 90-92 so that the entire apparatus is now incondition to cycle thermostatically. Assuming now that the space beingtemperature controlled is calling for heat as determined by athermostatic device, such as a room thermostat RT, the contacts of theroom thermostat RT are closed to complete an electrical circuit whichmay be traced as follows: the secondary coil of a transformer T has astepped down voltage (e.g. 24 volts) in response to energization of thetransformer primary coil from lines L1 and L2 of the usual voltage (e.g.110 volts); from the secondary conductor 100, through the closedcontacts of the room thermostat RT, the conductor 102, the fixed contact90, the movable contact 92 and blade 94, the conductor 104, the terminalpost 106 on the control device casing 10, the energizing coil 36, theterminal post 108 and the conductor 110 back to the secondary of thetransformer T.

- Energization of the coil 36 attracts the keeper 38 to theelectromagnet core 34 whereby the ball valve 30 is opened against thebias of the coil spring 42. Upon opening the ball valve 30, the bleedflow passages 24 and 26 communicate with the passage 28 whereby theoperating pressure chamber 22 is bled to the outlet 14. The restrictor29 assures a pressure drop in the chamber 22 and such decrease inpressure permits the main diaphragm valve 18 to open because of theinlet pressure of the fuel in the diaphragm chamber 20. With the mainvalve 18 opened, the, main flow of fuel proceeds to the main burner 16where it is ignited by the flame from the pilot burner 62.

As soon as the demand for heat is satisfied, the contacts of the roomthermostat RT are opened and the elec trical circuit for the electricactuator coil 36 is broken. Thus the ball valve 30 is closed and theunderside of the main diaphragm valve is subject to inlet pressure withthe bleed flow from bleed passage 24 proceeding through the bleedpassage 26 to the operating pressure chamber 22. With the main diaphragmvalve 18 being subject to equal pressures on opposite sides thereof, thecoil spring 32 biases the valve to a closed position and shut off theflow of fuel to the main burner. It is now apparent that the electricactuator for the ball valve 30 is thermostatically cycled by the roomthermostat RT to eifect open and closing of the main valve 18.

If at any time the flame from the pilot burner 62 should beextinguished, the subsequent cooling and contraction of the flameresponsive means causes the lever 70 to be biased to its upper position;thus the pilot flow valve 68 is closed and the electric switch -92 isopened. Even though the contacts of the room thermostat RT are closed atthis time, the opening of the electric switch 90-92 causesdeenergization of the electric actuator coil 36 so that the ball valve30 is closed resulting in closure of the main valve 18 as describedabove.

With the above arrangement, the apparatus may be reignited only bydepressing the push button 54, which does not require any connection orinterlock for manually operating the lever 70. shut off of all fuel flowis provided upon extinguishment of the flame from the pilot burner; inaddition safe lighting is effected during a resetting operation becausethe electric switch 9092 will not close until after the flame has beenrestored at the pilot burner.

Inasmuch as the preferred embodiment of the present invention is subjectto various modifications and numerous changes in detail, it is intendedthat all matter contained in the foregoing description or shown in theaccompanying drawing shall be interpreted as illustrative and not in alimiting sense.

What is claimed is:

1. Apparatus for controlling a flow of fuel in a fuel burning systemhaving main and pilot burners, the combination comprising a main controldevice casing having an inlet adapted to be connected to a fuel sourceand an outlet adapted to be connected to the main burner, main valvingmeans in said casing having electric actuator means for controlling afuel flow therethrough, conduit means for a flow of pilot burner fuelbypassing said main valving means, said conduit means having a firstbranch defining a regular pilot flow and a second branch defining areset pilot flow, a pilot control device housing disposed adjacent themain burner and having a pair of inlet passages and an outlet passage,one of said inlet passages communicating with said first branch and theother of said inlet passages communicating with said second branch,means mounting the pilot burner on said housing in communication withsaid outlet passage, valve means in said housing movable between a firstposition wherein the said one inlet passage is in communication withsaid outlet passage and a second position wherein the said one inletpassage is closed off from communication with said outlet passage, flameresponsive means having a portion disposed adjacent the pilot burner anda movable portion disposed in said housing, lever means in said housinghaving an intermediate portion operatively connected to said movableportion, one end of said lever means being operatively connected to saidvalve means, switch means in said housing operatively connected to theother end of said lever means, said lever means being operative in onedirection to close said switch means and to move said valve means to itsfirst postion and in another direction to open said switch means and tomove said valve means to its second position, and electric circuit meanselectrically connecting said switch means to said electric actuatormeans for actuating said main valving means and said valve means inresponse to movement of said flame responsive means.

2. The combination as recited in claim 1 wherein normally closed valvemeans is disposed in said second branch and includes operating means formovement to an open position during a resetting operation.

3. The combination as recited in claim 1 wherein said References Citedby the Examiner UNITED STATES PATENTS 1,031,913 7/1912 Casse 236-801,866,541 7/1932 Branche et al. 158-127 2,263,767 11/1941 Fox 158129 X2,512,173 6/1950 Ray 158-129 2,516,504 7/1950 Cerny et al. 158127 X2,652,110 9/1953 Main 158-129 X 3,107,856 10/1963 Holzboog et al. 158127X FREDERICK KETTERER, Primary Examiner.

1. APPARATUS FOR CONTROLLING A FLOW OF FUEL IN A FUEL BURNING SYSTEMHAVING A MAIN AND PILOT BURNERS, THE COMBINATION COMPRISING A MAINCONTROL DEVICE CASING HAVING AN INLET ADAPTED TO BE CONNECTED TO A FUELSOURCE AND AN OUTLET ADAPTED TO BE CONNECTED TO THE MAIN BURNER, MAINVALVING MEANS IN SAID CASING HAVING ELECTRIC, ACTUATOR MEANS FORCONTROLLING A FUEL FLOW THERETHTOUGH, CONDUIT MEANS FOR A FLOW OF PILOTBURNER FUEL BYPASSING SAID MAIN VALVING MEANS, SAID CONDUIT MEANS HAVINGA FIRST BRANCH DEFINING A REGULAR PILOT FLOW AND A SECOND BRANCHDEFINING A RESET PILOT FLOW, A PILOT CONTROL DEVICE HOUSING DISPOSEDADJACENT THE MAIN BURNER AND HAVING A PAIR OF INLET PASSAGES AND ANOUTLET PASSAGE, ONE OF SAID INLET PASSAGES COMMUNICATING WITH SAID FIRSTBRANCH AND THE OTHER OF SAID INLET PASSAGES COMMUNICATING WITH SAIDSECOND BRANCH, MEANS MOUNTING THE PILOT BURNER ON SAID HOUSING INCOMMUNICATION WITH SAID OUTLET PASSAGE, VALVE MEANS IN SAID HOUSINGMOVABLE BETWEEN A FIRST POSITION WHEREIN THE SAID ONE INLET PASSAGE ISIN COMMUNICATION WITH SAID OUTLET PASSAGE AND A SECOND POSITION WHEREINTHE SAID ONE INLET PASSAGE IS CLOSED OFF FROM COMMUNICATION WITH SAIDOUTLET PASSAGE, FLAME RESPONSIVE MEANS HAVING A PORTION DIS-